[BUG]
Even with chunk_objectid bug fixed, mkfs.btrfs can still caused stack
overflow when enabling extent-tree-v2 feature (need experimental
features enabled):
# ./mkfs.btrfs -f -O extent-tree-v2 ~/test.img
btrfs-progs v5.19.1
See http://btrfs.wiki.kernel.org for more information.
ERROR: superblock magic doesn't match
NOTE: several default settings have changed in version 5.15, please make sure
this does not affect your deployments:
- DUP for metadata (-m dup)
- enabled no-holes (-O no-holes)
- enabled free-space-tree (-R free-space-tree)
Label: (null)
UUID: 205c61e7-f58e-4e8f-9dc2-38724f5c554b
Node size: 16384
Sector size: 4096
Filesystem size: 512.00MiB
Block group profiles:
Data: single 8.00MiB
Metadata: DUP 32.00MiB
System: DUP 8.00MiB
SSD detected: no
Zoned device: no
=================================================================
[... Skip full ASAN output ...]
==65655==ABORTING
[CAUSE]
For experimental build, we have unified feature output, but the old
buffer size is only 64 bytes, which is too small to cover the new full
feature string:
extref, skinny-metadata, no-holes, free-space-tree, block-group-tree, extent-tree-v2
Above feature string is already 84 bytes, over the 64 on-stack memory
size.
This can also be proved by the ASAN output:
==65655==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffc4e03b1d0 at pc 0x7ff0fc05fafe bp 0x7ffc4e03ac60 sp 0x7ffc4e03a408
WRITE of size 17 at 0x7ffc4e03b1d0 thread T0
#0 0x7ff0fc05fafd in __interceptor_strcat /usr/src/debug/gcc/libsanitizer/asan/asan_interceptors.cpp:377
#1 0x55cdb7b06ca5 in parse_features_to_string common/fsfeatures.c:316
#2 0x55cdb7b06ce1 in btrfs_parse_fs_features_to_string common/fsfeatures.c:324
#3 0x55cdb7a37226 in main mkfs/main.c:1783
#4 0x7ff0fbe3c28f (/usr/lib/libc.so.6+0x2328f)
#5 0x7ff0fbe3c349 in __libc_start_main (/usr/lib/libc.so.6+0x23349)
#6 0x55cdb7a2cb34 in _start ../sysdeps/x86_64/start.S:115
[FIX]
Introduce a new macro, BTRFS_FEATURE_STRING_BUF_SIZE, along with a new
sanity check helper, btrfs_assert_feature_buf_size().
The problem is I can not find a build time method to verify
BTRFS_FEATURE_STRING_BUF_SIZE is large enough to contain all feature
names, thus have to go the runtime function to do the BUG_ON() to verify
the macro size.
Now the minimal buffer size for experimental build is 138 bytes, just
bump it to 160 for future expansion.
And if further features go beyond that number, mkfs.btrfs/btrfs-convert
will immediately crash at that BUG_ON(), so we can definitely detect it.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Tested-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Commit "btrfs-progs: prepare merging compat feature lists" tries to
merged "-O" and "-R" options, as they don't correctly represents
btrfs features.
But that commit caused the following bug during mkfs for experimental
build:
$ mkfs.btrfs -f -O block-group-tree /dev/nvme0n1
btrfs-progs v5.19.1
See http://btrfs.wiki.kernel.org for more information.
ERROR: superblock magic doesn't match
ERROR: illegal nodesize 16384 (not equal to 4096 for mixed block group)
[CAUSE]
Currently btrfs_parse_fs_features() will return a u64, and reuse the
same u64 for both incompat and compat RO flags for experimental branch.
This can easily leads to conflicts, as
BTRFS_FEATURE_INCOMPAT_MIXED_BLOCK_GROUP and
BTRFS_FEATURE_COMPAT_RO_BLOCK_GROUP_TREE both share the same bit
(1 << 2).
Thus for above case, mkfs.btrfs believe it has set MIXED_BLOCK_GROUP
feature, but what we really want is BLOCK_GROUP_TREE.
[FIX]
Instead of incorrectly re-using the same bits in btrfs_feature, split
the old flags into 3 flags:
- incompat_flag
- compat_ro_flag
- runtime_flag
The first two flags are easy to understand, the corresponding flag of
each feature.
The last runtime_flag is to compensate features which doesn't have any
on-disk flag set, like QUOTA and LIST_ALL.
And since we're no longer using a single u64 as features, we have to
introduce a new structure, btrfs_mkfs_features, to contain above 3
flags.
This also mean, things like default mkfs features must be converted to
use the new structure, thus those old macros are all converted to
const static structures:
- BTRFS_MKFS_DEFAULT_FEATURES + BTRFS_MKFS_DEFAULT_RUNTIME_FEATURES
-> btrfs_mkfs_default_features
- BTRFS_CONVERT_ALLOWED_FEATURES -> btrfs_convert_allowed_features
And since we're using a structure, it's not longer as easy to implement
a disallowed mask.
Thus functions with @mask_disallowed are all changed to using
an @allowed structure pointer (which can be NULL).
Finally if we have experimental features enabled, all features can be
specified by -O options, and we can output a unified feature list,
instead of the old split ones.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The tool IWYU (include what you use) suggests to remove and add some
includes. This is only partial to avoid accidental build breakage, the
includes are entangled and will have to be cleaned in the future again.
Signed-off-by: David Sterba <dsterba@suse.com>
Block group tree feature is completely a standalone feature, and it has
been over 5 years before the initial introduction to solve the long
mount time.
I don't really want to waste another 5 years waiting for a feature which
may or may not work, but definitely not properly reviewed for its
preparation patches.
So this patch will separate the block group tree feature into a
standalone compat RO feature.
There is a catch, in mkfs create_block_group_tree(), current
tree-checker only accepts block group item with valid chunk_objectid,
but the existing code from extent-tree-v2 didn't properly initialize it.
This patch will also fix above mentioned problem so kernel can mount it
correctly.
Now mkfs/fsck should be able to handle the fs with block group tree.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Since we cannot create ext*/reiserfs on a zoned device, it is useless to
allow ZONED feature when converting a file system. Drop ZONED flag from
BTRFS_CONVERT_ALLOWED_FEATURES.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The free space tree is a better way to track the free space and has been
tested in the wild for a long time. The backward compatibility is
sufficient, several long term kernels. On-line conversion from v1 to v2
can be done by mount, switching from v2 to v1 can be done by 'btrfs
check'.
Issue: #295
Signed-off-by: David Sterba <dsterba@suse.com>
The no-holes feature reduces consumption of metadata by not representing
file holes. Reducing metadata is a good thing in general, this is the
main goal to enable this by default.
There's a drawback, related to the missing information about holes. The
'check' tool cannot use it to cross-reference extent information and in
some cases may not be able to detect a problem.
The no-hole feature can be also enabled by 'btrfstune -n' on an
unmounted filesystem.
Issue: #405
Signed-off-by: David Sterba <dsterba@suse.com>
With the zoned feature enabled, a zoned block device-aware btrfs
allocates block groups aligned to the device zones and always written in
sequential zones at the zone write pointer position.
It also supports "emulated" zoned mode on a non-zoned device. In the
emulated mode, btrfs emulates conventional zones by slicing the device
into fixed-size zones.
We don't support conversion from the ext4 volume with the zoned feature
because we can't be sure all the converted block groups are aligned to
zone boundaries.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are several problems for current sectorsize check:
- No check at all for sectorsize
This means you can even specify "-s 62k".
- No way to specify sectorsize smaller than page size
Fix all these problems by:
- Introduce btrfs_check_sectorsize()
To do:
* power of 2 check for sectorsize
* lower and upper boundary check for sectorsize
* warn about sectorsize mismatch with page size
- Remove the max() between page size and sectorsize
This allows us to override the sectorsize for 64K page systems.
- Make nodesize calculation based on sectorsize
No need to use page size any more.
Users who specify sectorsize manually really know what they are doing,
and we have warned them already.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a runtime feature (-R) flag for the free space tree. A filesystem
that is mkfs'd with -R free-space-tree then mounted with no options has
the same contents as one mkfs'd without the option, then mounted with
'-o space_cache=v2'.
The only tricky thing is in exactly how to call the tree creation code.
Using btrfs_create_free_space_tree as is did not quite work, because an
extra reference to the eb (root->commit_root) is leaked, which mkfs
complains about with a warning. I opted to follow how the uuid tree is
created by adding it to the dirty roots list for cleanup by
commit_tree_roots in commit_transaction. As a result,
btrfs_create_free_space_tree no longer exactly matches the version in
the kernel sources.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Add support for enabling quotas at mkfs time. The qgroup accounting will
be consistent, ie. works with --rootdir.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Make the features structures more generic to allow mkfs-time and
mount-time sets to be defined.
This provides base for later mkfs support of mount-time features like
quotas.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Qu Wenruo
David Sterba
Naohiro Aota
Boris Burkov